Much of it, probably not. It will need an 8 bonded channel upstream to get close to 20Mbps, so you'll need a different modem from most of the D3s available ... they currently only use 4.

20 may come, but not for a while, we've been stuck on very low uploads for 10 years!

Actually 20mbps is possible with 4 upstream channels. I posted a screen shot of my modem when I had signal issues and it only connected to one upstream channel but the modem was still set at 10mbps upload and it was able to get 7mbps upload with just 1 upstream channel so if rogers would just set modem at 20mbps then 4 upstream channel will be able to support it. It all depends on the fact that only a handful can get it because there just won't be enough time slots if a ton of modems had 20mbps and all wanted to use it to its fullest but it IS possible, no doubt with a few modems per node.

But like you said with 8 up stream channels it will work a lot better, the more upstream channels there are the more time slots.